Miniature pacemaker designed to be implanted in fetuses

The relative sizes of a standard pacemaker and the new fetus-sized model (Image: CHLA)

In the near future, it's entirely possible that babies with heart defects will be born with complete pacemakers already installed. That's because scientists at Children's Hospital Los Angeles (CHLA) and the University of Southern California have developed the world's first fully-implantable pacemaker for fetuses.

The device is intended specifically for in-utero implantation in fetuses suffering from congenital heart block. This is a defect that affects the heart's electrical system, dangerously lowering the heart rate.

Previous attempts at addressing the malady have involved implanting the heart-stimulating electrodes of a regular adult-sized pacemaker in the fetus, with wires leading from it to the rest of the device, which was located outside the womb. According to the researchers, however, all of those attempts failed. This was likely due to the fact that the electrodes were pulled loose from the fetus' heart as it moved around.

By contrast, the new device is small enough that the whole thing can be implanted. No matter how much the fetus squirms, everything should stay attached and in place.

"We now have a pacemaker that can be implanted in-utero, potentially without harm to the fetus or the mom," said Dr. Ramen H. Chmait, Director of the CHLA-USC Institute for Maternal-Fetal Health. "This novel device provides a real opportunity to prevent miscarriage and premature birth in babies affected with these abnormalities."